Liquid toner compositions used in imaging processes generally comprise pigmented polymeric particles, a carrier liquid and charge director. Certain imaging processes use intermediate transfer members which receive an image from the photoconductor and transfer it to the final substrate, e.g. paper. When an intermediate transfer member (ITM) is used, the liquid toners should meet the following three criteria, namely, they should transfer well from the photoconductor to the ITM; they should transfer well from the ITM to the final substrate; and they must fuse well to the final substrate so that the image is abrasion resistant.
The transfer steps are preferably effected at as low a temperature as possible, because low temperature operations prolong the life of the ITM and the photoconductor. The liquid toners presently used in the art frequently contain Elvax.RTM. II polymers or Surlyn.RTM. polymers. While the Elvax II polymers generally transfer and fix well, some of them are too soft in the presence of carrier liquid to resist squashing during transfer to and from the intermediate transfer member. Those which do transfer and fix well require intermediate transfer member temperatures which marginally effect the operation of the photoreceptor and reduce the life of the intermediate transfer member.
In general Surlyn polymers wet paper substrates poorly and require very high temperatures for fixing on paper. These materials are, however, very hard and therefore are very abrasion resistant when they are fixed to paper at high temperatures.